hdr wtf?
(Deutsche Fassung dieses Eintrags)
Digital cameras cannot take pictures the way humans perceive it. The human eye has a higher dynamic range than the camera.
The easiest example is an object with very bright background: the human eye can see textures on the object as well as in the background. When taking a picture of the object, the camera will make a choice: either the textures of the object appear, and the background is completely white - or the texture of the background are visible, and the foreground will be too dark.
The solution to this dilemma (except from cut-out and mask) is to increase the dynamic range of an image: the amount of data stored in the a pixel is doubled. High dynamic range (HDR) images cannot be displayed on a normal computer screen or printer prior to mapping the higher range (32-bit) to the conventional range (16-bit).
Because there are no HDR compatible cameras on the (consumer) market yet, the process works as follows: the information of two or more (usually 3-5) images of the same scenery with different exposures is combined into one image. The range of image is then 'compressed' to fit standard viewing methods.
When HDR will be implemented directly in the cameras, the photographer will not need to worry anymore about over- or underexposed pictures. The decision about the 'exposure' will be post-production. I'm looking forward to that!
More information about HDR:
wikipedia.org/wiki/High_dynamic_range_imaging
hdrsoft.com
Note: the Photomatix Pro Software from this website may be trial licensed only, but can still be used to generate pictures without watermark: use the Tone Compressor method instead of Details enhancer when tone mapping, and you will get no watermarks!
